George t



(No Model.)

G. T. BEOHTOL. DIFFERENTIAL OALIPER POINT.

No. 482,331. Patented Sept. 13, 1892.

W/TN SE8: U/ENTO/Y I .QMMQ y B) W MW ATTOBN v UNITED STATES-PATENT ()FFICE.

GEORGE T. BEOHTOL, OF ELMIRA, NEW YORK, ASSIGNOR OF ONE-HALF TO FRED. WV. PARSONS, OF SAME PLACE.

DIFFERENTIAL CALlPER-POINT.

SPECIFICATION forming part of Letters Patent No. 482,331,dated September 13, 1892.

Application filed March 15, 1892. Serial No. 425,068. (No model.)

To all whom it may concern: tances between contact points will be indi- 50 Be it known that I, GEORGE T. BECHTOL, a cated. Such markings are shown in Fig. 1 in citizen of the United States, residing in the the shape of fractions representing fractions city of Elmira, county of Chemung, State of of an inch or other unit.

New York, have "invented a new and useful Between the pins are sockets 11, into which Improvement in Measuring Devices, of which the bolt or latch projects, said latch being the following is a full, clear, and exact defree to move to and fro through the bearings scription, reference being had to the accom- 9 in order to engage with the sockets in the panying drawings, forming part of this speciwheel, as above described.

[0 fication. In Figs. 2 and 3 are shown views of a modi- My invention relates to instruments for fication of the device in the form of an atmeasuring objects by increasing or diminishtachment to be fitted to any calipers. Here ing the distance between the contact-points. another means for locking the wheel is shown, The object of my invention is to, first, prothe same being a spring H, attached to the l 5 vide means for easily and accurately adjustback of the device, as shown in Figs. 2 and 3,

ing the contact-points; second, to do this withsaid spring having a projecting point or pin out altering the adjustment of the joint it- I, free to move in a hole in the back of the self, and, third, to provide means for making piece F and of sufficientlength to project into the amount of this adjustment definite and small indents or notches in the back face of 20 certain. the wheel D,asshown in J, Fig. 2,said indents These ends I accomplish by the device illusbeing so placed relatively to the pins or spokes 7o trated in the accompanying drawings, which of the wheel that when the pin Iis pressed by form apart of this specification, and in which the spring into an indent a corresponding similar letters and figures of reference refer spoke will be in position for measuring, as 2 5 to similar parts throughout the various views. below described. The shank F has the socket Figure 1 is a side elevation showing the or groove G, formed in such away as to secure various parts assembled, illustrating one it firmly to the caliper-leg. Ido not,however, means of accomplishing the proposed ends. confine myself to this means of attaching it. Fig. 2 is an elevation of amodification of this The operation of the device is as follows: 0 device, showing it as made in form of an at- The caliper-legs are adjusted by means of the tachment to be applied to any calipers. Fig. screw V and milled head P, Fig. 1, the wheel 3 is a side elevation of the device shown in Dbeing so turned that either thelongest spoke Fig. 2, showing, also, another means for lock- 1 1 or the shortest spoke 8 is in position of coning the wheel. tact-point, as shown in Fig. 1, thelatch 10 or 35 Referring'to Fig. 1, B B represent the ordithe spring and pin H and I, Fig. 3,holdingthe nary calipers, with a screw adjustment V P wheel firmly in position. Upon releasing the 8 5 either inside, as in this instance, or outside. looking attachmentthelatch or spring-pin A is the spring-joint. and on turning the wheel a new spoke dif- O is the usual contact-point. fering in length from the first by a definite 40 The wheel D, revolving on the pivot E, may and known amount is brought into position, I

be made a permanent part of the caliper-leg, thus adjusting the distance between the conas in Fig. 1,or may be part of an attachment, tact-points definitely and to a known amount, as in Figs. 2 and 3. In Fig. 1 the wheel D has as shown by the scale or index, greater or less spokes or pins 1 2 8 4 5 6, varying from each than as first adjusted, according as the wheel 45 other in length by some definite fraction of a is turned in one direction or another, and

unit of measure, as tenths of an inch, without changing the adjustmentof the cali- 93 The wheel may be marked to constitute a per-legs themselves, the operation being the scale or index by which at different stages of same on either inside or outside calipers. I revolution corresponding variations in disdo not, however, limit myself to the above means and form of construction herein described.

What I claim, and desire to secure by Letters Patent, is-

1. In a measuring device, a wheel or cam suitably mounted and having one or more points on its periphery set eccentrically with reference to the center, whereby the distance between contact-points may be increased or diminished at will, substantially as described.

2. In a measuring device, the combination of ordinary calipers with a wheel suitably mounted, having one. or more spokes or projections of unequal lengths from the center, varying from each other by a definite and certain amount, and provided with means for locking said wheel in position, and a graduated scale or index, substantially as described.

3. The combination, in a measuring device, of a body suitably mounted, comprising one or more contact-points whose motion about its axis increases or diminishes the distance between the measuring-points, means for locking the same,'and a graduated scale or index adapted to indicate the amount of adj ustment,

substantially as and for the purposes set forth.

G. T; BECHTOL. Witnesses:

T. WARREN BIRD, JOHN W. LOVELAND. 

